1. Field of the Invention
This invention relates to an oil in water (hereinafter abbreviated to "O/W") type emulsion composition comprising L-arginine salt of a higher aliphatic phosphate, and an .alpha.-monoalkyl glyceryl ether. More particularly, the invention is directed to an O/W type emulsion composition which has a small viscosity decrease at a high temperature and a small viscosity increase at a low temperature, is stable during storage over a long period of time, provides good feelings and a moisture retaining effect on use to the skin, and yet has an excellent safety.
2. Prior Art
In recent years, it is considered desirable that the skin cosmetics has a pH range of 5.0-6.5 which is commensurate with the pH range of the human skin. Thus, there is a tendency of increasing use of such weakly acidic emulsion type cosmetics. In order to produce the weakly acidic emulsion composition there has been conventionally used emulsifiers such as non-ionic surface active agents of an ethylene oxide addition type, alkyl sulfates, salts of N-acylated glutamic acid and the like, and emulsification assistant agents, including, for example, higher alcohols such as cetanol or higher fatty acids such as stearic acid.
The aforementioned emulsifiers, however, possess a drawback in that the viscosity of the emulsions prepared therefrom decreases at a high temperature and increases at a low temperature. In particular, the easiness of taking out the emulsion from the bottle, the solidity of the cream, and the properties of the cream for handling with fingers have a dependency on the temperature at which the product is used. Moreover, the change of the temperature causes the gloss of the cream to diminish and gives adverse effects on the spreadability of the cream and its fitness or affinity to the skin.
Therefore, there has been a demand for suitable combination of emulsifiers and emulsification assistant agents which may provide weakly acidic emulsions and creams of which viscosity, appearance, solidity and feelings on use do not change by the change of temperature.